1 /* 2 * Copyright 2006 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkColor.h" 9 #include "SkColorPriv.h" 10 #include "SkFixed.h" 11 12 SkPMColor SkPreMultiplyARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) { 13 return SkPremultiplyARGBInline(a, r, g, b); 14 } 15 16 SkPMColor SkPreMultiplyColor(SkColor c) { 17 return SkPremultiplyARGBInline(SkColorGetA(c), SkColorGetR(c), 18 SkColorGetG(c), SkColorGetB(c)); 19 } 20 21 /////////////////////////////////////////////////////////////////////////////// 22 23 static inline SkScalar ByteToScalar(U8CPU x) { 24 SkASSERT(x <= 255); 25 return SkIntToScalar(x) / 255; 26 } 27 28 static inline SkScalar ByteDivToScalar(int numer, U8CPU denom) { 29 // cast to keep the answer signed 30 return SkIntToScalar(numer) / (int)denom; 31 } 32 33 void SkRGBToHSV(U8CPU r, U8CPU g, U8CPU b, SkScalar hsv[3]) { 34 SkASSERT(hsv); 35 36 unsigned min = SkMin32(r, SkMin32(g, b)); 37 unsigned max = SkMax32(r, SkMax32(g, b)); 38 unsigned delta = max - min; 39 40 SkScalar v = ByteToScalar(max); 41 SkASSERT(v >= 0 && v <= SK_Scalar1); 42 43 if (0 == delta) { // we're a shade of gray 44 hsv[0] = 0; 45 hsv[1] = 0; 46 hsv[2] = v; 47 return; 48 } 49 50 SkScalar s = ByteDivToScalar(delta, max); 51 SkASSERT(s >= 0 && s <= SK_Scalar1); 52 53 SkScalar h; 54 if (r == max) { 55 h = ByteDivToScalar(g - b, delta); 56 } else if (g == max) { 57 h = SkIntToScalar(2) + ByteDivToScalar(b - r, delta); 58 } else { // b == max 59 h = SkIntToScalar(4) + ByteDivToScalar(r - g, delta); 60 } 61 62 h *= 60; 63 if (h < 0) { 64 h += SkIntToScalar(360); 65 } 66 SkASSERT(h >= 0 && h < SkIntToScalar(360)); 67 68 hsv[0] = h; 69 hsv[1] = s; 70 hsv[2] = v; 71 } 72 73 SkColor SkHSVToColor(U8CPU a, const SkScalar hsv[3]) { 74 SkASSERT(hsv); 75 76 U8CPU s = SkUnitScalarClampToByte(hsv[1]); 77 U8CPU v = SkUnitScalarClampToByte(hsv[2]); 78 79 if (0 == s) { // shade of gray 80 return SkColorSetARGB(a, v, v, v); 81 } 82 SkFixed hx = (hsv[0] < 0 || hsv[0] >= SkIntToScalar(360)) ? 0 : SkScalarToFixed(hsv[0]/60); 83 SkFixed f = hx & 0xFFFF; 84 85 unsigned v_scale = SkAlpha255To256(v); 86 unsigned p = SkAlphaMul(255 - s, v_scale); 87 unsigned q = SkAlphaMul(255 - (s * f >> 16), v_scale); 88 unsigned t = SkAlphaMul(255 - (s * (SK_Fixed1 - f) >> 16), v_scale); 89 90 unsigned r, g, b; 91 92 SkASSERT((unsigned)(hx >> 16) < 6); 93 switch (hx >> 16) { 94 case 0: r = v; g = t; b = p; break; 95 case 1: r = q; g = v; b = p; break; 96 case 2: r = p; g = v; b = t; break; 97 case 3: r = p; g = q; b = v; break; 98 case 4: r = t; g = p; b = v; break; 99 default: r = v; g = p; b = q; break; 100 } 101 return SkColorSetARGB(a, r, g, b); 102 } 103 104 /////////////////////////////////////////////////////////////////////////////////////////////////// 105 #include "SkPM4f.h" 106 #include "SkNx.h" 107 #include "SkHalf.h" 108 109 SkPM4f SkPM4f::FromPMColor(SkPMColor c) { 110 Sk4f value = SkNx_cast<float>(Sk4b::Load(&c)); 111 SkPM4f c4; 112 (value * Sk4f(1.0f / 255)).store(&c4); 113 return c4; 114 } 115 116 SkColor4f SkPM4f::unpremul() const { 117 float alpha = fVec[A]; 118 if (0 == alpha) { 119 return { 0, 0, 0, 0 }; 120 } else { 121 float invAlpha = 1 / alpha; 122 return { alpha, fVec[R] * invAlpha, fVec[G] * invAlpha, fVec[B] * invAlpha }; 123 } 124 } 125 126 void SkPM4f::toF16(uint16_t half[4]) const { 127 for (int i = 0; i < 4; ++i) { 128 half[i] = SkFloatToHalf(fVec[i]); 129 } 130 } 131 132 uint64_t SkPM4f::toF16() const { 133 uint64_t value; 134 this->toF16(reinterpret_cast<uint16_t*>(&value)); 135 return value; 136 } 137 138 SkPM4f SkPM4f::FromF16(const uint16_t half[4]) { 139 return {{ 140 SkHalfToFloat(half[0]), 141 SkHalfToFloat(half[1]), 142 SkHalfToFloat(half[2]), 143 SkHalfToFloat(half[3]) 144 }}; 145 } 146 147 #ifdef SK_DEBUG 148 void SkPM4f::assertIsUnit() const { 149 auto c4 = Sk4f::Load(fVec); 150 SkASSERT((c4 >= Sk4f(0)).allTrue() && (c4 <= Sk4f(1)).allTrue()); 151 } 152 #endif 153 154 /////////////////////////////////////////////////////////////////////////////////////////////////// 155 156 SkColor4f SkColor4f::FromColor(SkColor c) { 157 Sk4f value = SkNx_shuffle<3,2,1,0>(SkNx_cast<float>(Sk4b::Load(&c))); 158 SkColor4f c4; 159 (value * Sk4f(1.0f / 255)).store(&c4); 160 return c4; 161 } 162 163 SkColor4f SkColor4f::Pin(float a, float r, float g, float b) { 164 SkColor4f c4; 165 Sk4f::Min(Sk4f::Max(Sk4f(a, r, g, b), Sk4f(0)), Sk4f(1)).store(c4.vec()); 166 return c4; 167 } 168 169 SkPM4f SkColor4f::premul() const { 170 auto src = Sk4f::Load(this->pin().vec()); 171 float srcAlpha = src[0]; // need the pinned version of our alpha 172 src = src * Sk4f(1, srcAlpha, srcAlpha, srcAlpha); 173 174 #ifdef SK_PMCOLOR_IS_BGRA 175 // ARGB -> BGRA 176 Sk4f dst = SkNx_shuffle<3,2,1,0>(src); 177 #else 178 // ARGB -> RGBA 179 Sk4f dst = SkNx_shuffle<1,2,3,0>(src); 180 #endif 181 182 SkPM4f pm4; 183 dst.store(&pm4); 184 return pm4; 185 } 186
